This invention relates to a thermosetting resin composition containing unsaturated polyester resins modified with a dicyclopentadiene concentrate, a vinyl aromatic monomer, and a dicyclopentadiene alkenoate and laminates prepared from them. More specifically, the invention relates to compositions containing polyester resins produced by reacting a glycol, an olefinically unsaturated dicarboxylic acid or anhydride, a saturated dicarboxylic acid or anhydride, and 10 to 100 mole percent based on the acid of a dicyclopentadiene concentrate. These polyester resins are blended with styrene and dicyclopentadiene acrylate to produce a thermosetting resin composition or blend.
It is well known from the report by P. L. Smith, et al. "The Use of Dicyclopentadiene in Polyesters", Proceedings of the 22nd Annual Technical Conference, S.P.I., Reinforced Plastics Division, Washington, D.C. (1967) and the article by R. Zimmermann, et al. "Modification of Unsaturated Polyesters with Dicyclopentadiene" Qette-Serfen-Anstrichmittel 66, #9, 670-678 (1964), and U.S. Pat. No. 3,347,806 that polyesters can be modified with dicyclopentadiene.
The use of a low purity dicyclopentadiene concentrate to make polyester resins is disclosed in U.S. Pat. No. 4,029,848 dated June 14, 1977.